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Uncovering the Footprints of Erosion by On-Farm Maize Cultivation in a Hilly Tropical Landscape
Chaminda Egodawatta,Peter Stamp,Ravi Sangakkara
Agriculture , 2013, DOI: 10.3390/agriculture3030556
Abstract: A hilly region in Sri Lanka was considered to be degraded by erosion driven by intensive tobacco production, but what are reliable indicators of erosion? In addition to determining soil chemical and physical traits, maize was cropped with Nitrogen, Phosphorus and Potassium (NPK, PK) recommended mineral fertilization and without fertilizer (ZERO) in two major seasons(October–January in 2007/2008 and 2008/2009—Seasons 1 and 2 respectively) on 92 farms at inclinations ranging from 0% to 65%. In a subset of steep farms ( n = 21) an A horizon of 6 cm rather than of 26 cm was strong proof of erosion above 30% inclination. Below the A level, the thickness of the horizon was unaffected by inclination. Soil organic matter contents (SOM) were generally low, more so at higher inclinations, probably due to greater erosion than at lower inclination. Maize yields decreased gradually with increasing inclination; at ZERO, effects of climate and soil moisture on yield were easier determined and were probably due to long-term erosion. However, despite an initial set of 119 farms, an exact metric classification of erosion was impossible. NPK strongly boosted yield. This was a positive sign that the deficits in chemical soil fertility were overriding physical soil weaknesses. The study illustrated that chemical soil fertility in these soils is easily amenable to modifications by mineral and organic manures.
Growth and Nutrient Use Efficiencies of Yams (Dioscorea spp.) Grown in Two Contrasting Soils of West Africa
Lucien N'Guessan Diby,Bi Tra Tie,Olivier Girardin,Ravi Sangakkara,Emmanuel Frossard
International Journal of Agronomy , 2011, DOI: 10.1155/2011/175958
Abstract: Fertilization is an important management strategy of yams (Dioscorea spp.) especially when grown in degraded soils. A field study evaluated the leaf numbers, leaf area indices, crop growth, yields, and nitrogen (N) and potassium (K) use efficiencies of D. alata and D. rotundata in C?te d'Ivoire when grown in two contrasting soils with and without fertilizer. D. alata had a lower number of leaves per vine, although leaf area indices were higher, and the leaves were retained for a longer period than in D. rotundata. In all situations, the yields of D. alata were significantly higher, and fertilizers promoted growth of shoots, roots, tubers, and, thus, final yields especially in the low fertile savanna soil. The beneficial impact of fertilizer on yields was significantly lower in the fertile forest soils. The nutrient use agronomic efficiencies indicated the impact of both N and K in promoting yields especially under nonfertilized conditions. 1. Introduction Yams (Dioscorea) are a vital component of the agricultural sector of West Africa, both in terms of food, social, and cultural values [1]. In these regions, D. alata and D. rotundata are cultivated in a range of soils, from degraded smallholdings through low fertile savannas to newly cleared forest sites, which have a high degree of fertility. Most farmers of the region cultivate yams in smallholdings under low-fertility conditions, except in some instances where short fallows are incorporated into the cropping systems to rejuvenate the soil fertility [2]. Thus, despite increases in land areas being cultivated in West Africa, yam production has remained static [3], indicating a gradual decline in yields per unit land area. Crop management plays an important role in procuring high yields in tropical tuber crops [4]. A major constraint for enhancing yam productivity is low soil fertility, both in terms of macro- and micronutrient deficiency [5]. This is because yams are high-nutrient-demanding species [6], and when planted in low-fertility soils under subsistence conditions as done in smallholder systems of West Africa, yields are low, varying between 9 and 10 t?ha?1 compared with a potential yield of 51 t?ha?1 for D. alata and 27 for t?ha?1 D. rotundata [7]. Hence, research on possible methods to enhance yam productivity is needed to produce this culturally important and economically viable species especially under conditions of West Africa. Research on the impact of fertilizers on Dioscorea yams is scarce. Some studies show the lack of yield response of Dioscorea to applied phosphorus [8], and to both
Fighting Uncertainty with Uncertainty: A Baby Step  [PDF]
Ravi Kashyap
Theoretical Economics Letters (TEL) , 2017, DOI: 10.4236/tel.2017.75097
Abstract: We can overcome uncertainty with uncertainty. Using randomness in our choices and in what we control, and hence in the decision making process, we could potentially offset the uncertainty inherent in the environment and yield better outcomes. The example we develop in greater detail is the news-vendor inventory management problem with demand uncertainty. We briefly discuss areas, where such an approach might be helpful, with the common prescription, “Don’t Simply Optimize, Also Randomize; perhaps best described by the termRandoptimization”. 1) News-Vendor Inventory Management; 2) School Admissions; 3) Journal Submissions; 4) Job Candidate Selection; 5) Stock Picking; 6) Monetary Policy. This methodology is suitable for the social sciences since the primary source of uncertainty is the members of the system themselves and presently, no methods are known to fully determine the outcomes in such an environment, which perhaps would require being able to read the minds of everyone involved and to anticipate their actions continuously. Admittedly, we are not qualified to recommend whether such an approach is conducive for the natural sciences, unless perhaps, bounds can be established on the levels of uncertainty in a system and it is shown conclusively that a better understanding of the system and hence improved decision making will not alter the outcomes.
Antimicrobial Activity of Purified Toxins from Crossopriza lyoni (Spider) against Certain Bacteria and Fungi  [PDF]
Ravi Kumar Gupta, Ravi Kant Upadhyay
Journal of Biosciences and Medicines (JBM) , 2016, DOI: 10.4236/jbm.2016.48001
Abstract: Toxins from spider venom Crossopriza lyoni were subjected to purify on a Sepharose CL-6B 200 column. These were investigated for its antibacterial and antifungal activity against 13 infectious microbial pathogenic strains. Antimicrobial susceptibility was determined by using paper disc diffusion and serial micro-dilution assays. Triton X-100 (0.1%) proved to be a good solubilizing agent for toxin/proteins. Higher protein solubilization was observed in the supernatant than in the residue, except TCA. The elution pattern of purified and homogenized sting glands displayed two major peaks at 280 nm. First one was eluted in fraction no. 43 - 51 while second one after fraction no. 61 - 90. From gel filtration chromatography total yield of protein obtained was 67.3%. From comparison of gel chromatographs eluted toxins peptide molecular weight was ranging from 6.2 - 64 kD. Toxin peptides have shown lower MIC values i.e. 7.5 - 15 μg/ml against K. pneumoniae, E. coli, L. acidophilus, B. cereus; against S. aureus and M. luteus that the broad spectrum antibiotics i.e. tetracycline and ampicillin. In tests, larger inhibition zone diameter was obtained in comparison to control. Diameter of inhibition zones obtained in spider toxins at a concentration range of 197.12 - 0.96 g/ml for E. coli was 17.86 ± 0.21, Bacillus cereus 19.13 ± 0.21, L. acidophilus 16.83 ± 0.25, Micrococcus luteus 18.46 ± 0.17, S. aeurus 16.23 ± 0.19, Klebsiella pneumoniae 21.83 ± 0.16, Salmonella typhi 16.16 ± 0.21, Vibrio cholera 18.66 ± 0.21, Pseudomonas aeruginosa 18.66 ± 0.21, Aspergillus niger 22.9 ± 0.24, Candida albicans 24.66 ± 0.28, Rhizopus stolonifer 21.1 ± 0.16. Spider toxins generate cytotoxic effect on bacterial cells that results in heavy cell death. No doubt spider toxins can be used as alternate of broad spectrum antibiotics.
Assessment of bone condition by acoustic emission technique: A review  [PDF]
Sharad Shrivastava, Ravi Prakash
Journal of Biomedical Science and Engineering (JBiSE) , 2009, DOI: 10.4236/jbise.2009.23025
Abstract: The paper deals with the review of acoustic emission technique in biomedical field. The re-view is done with the aim to provide an overview of the use of AE technique in biomedical field, mainly concentrated on the AE behavior of bone under different loading conditions, its depend-ence on strain rate, in osteoporosis, monitoring the fracture healing process of bone. The over-all conclusion from the review was that almost all the studies in bone indicated that the initial AE occurs only in the plastic region and just prior to yield. That means the use of AE tech-nique for clinical application cannot be consid-ered as a safe technique, but the early occur-rence of AE events from callus promises the application of AE technique for monitoring the fracture healing process. The negligible effect of soft tissues on AE response of bone prom-ises AE to become a non-invasive method for assessment of bone condition.
Influence of Benzoate on Substituent Benzoic Acids with Implications on Spectroscopic Studies through Inter Molecular Hydrogen Bonding  [PDF]
Ravi Shankar Kumar
Materials Sciences and Applications (MSA) , 2011, DOI: 10.4236/msa.2011.26068
Abstract: Comprehensive study on the homologous series of compounds in the form A-R- HHB are synthesized with central rigid core as benzoic acids together with substituent’s alkoxy (A) and alkyl (R) group of equal chain lengths from 5 to 10 are connected to hexyl-p-hydroxy benzoate (HHB). These complexes form supramolecular structures by self assembling process due to intermolecular hydrogen bonding. The formation is analyzed with techniques involving polarizing optical microscope, infrared spectroscopy, proton NMR spectroscopy and powdered X-ray diffraction. Results suggest that complexes arise from both A and R groups exhibit enantiotropic layered texture of crystal G phase observed by microscopic studies due to flexible nature of mesogenics. The conversion of free to molecular complexes is determined with variations in spectral shifts between its terminal groups COOH and OH of molecules involving inter molecular hydrogen bonding and its bonding index by FTIR spectra. The changes in structure and dynamics due to hydrogen bonding in complexes are convinced by proton NMR spectra with chemical shifts in specified range. The defects in crystal structure responsible for enantiotropic phenomena are analyzed by powdered X ray diffraction.
Effects of plant latex based anti-termite formulations on Indian white termite Odontotermes obesus (Isoptera: Odontotermitidae) in sub-tropical high infestation areas  [PDF]
Ravi Kant Upadhyay
Open Journal of Animal Sciences (OJAS) , 2013, DOI: 10.4236/ojas.2013.34042
Abstract: In the present investigation various bioassays were conducted to evaluate the anti-termite efficacy of plant latex based formulations to control population of Indian white termite in subtropical soil. Results reveal that crude latex, its fractions and combinatorial fractions have shown very high toxicity against O. obesus. The LD50 values for different latex fractions of 24 h were in a range of 5.0-17.613 μg/mg while combined mixtures of Calotropis procera have shown synergistic activity against termites and caused comparably high mortality with LD50 1.987-6.016 μg/mg. The mortality rate was found dose and time dependent as it was found to be increased with an increase in dose and exposure period. In olfactometry tests, C. procera latex solvent fractions have shown significant repellency at a very low dose 0.010-0.320 μg/mg. Interestingly, solvent fractions have significantly repelled large numbers of worker termites due to volatile action of active components of latex and different additives. ED50 values obtained in crude latex were 0.121 μg/mg body weights while combinatorial formulations have shown ED50 in between 0.015-0.036 μg/mg. Statistical analysis of repelled and un-repelled termites gave a low Chi-square value (X2
Antimicrobial Activity of Fruit Latexes from Ten Laticiferous Plants  [PDF]
Ravi Kant Upadhyay
American Journal of Plant Sciences (AJPS) , 2015, DOI: 10.4236/ajps.2015.63053
Abstract: In the present investigation antibacterial activity of latexes from ten Indian plant species Spondias dulcis (Amra), Diospyros melanoxylon (Tendu), Terminalia bellirica (Wahera), Ficus glomerata (Gular), Phyllanthus emblica (Awla), Thevetia nerifolia (Kaner), Carica papaya (Papita), Calotropis procera (Ak), Ficus benghalensis (Bargad), Atrocarpus heterophyllus (Kathal) collected from Go-rakhpur, North India were determined in various in vitro systems. MIC (minimum inhibitory concentration) and MBC (minimum bactericidal concentration) values were determined in growth inhibitory bioassays by using different increasing concentrations of various latex extracts. Latex samples were diluted by using serial micro dilution method up to 10-10 method with Luria broth culture medium. These values were obtained significantly 2 - 3 times lower than that of broad spectrum antibiotic drugs. Besides this, inhibition zone diameters were measured in agar disc diffusion assay. A known volume i.e. 0.1 - 20 μg/μl of each latex were coated on separate sterile filter paper discs (Whatman No. 1) measuring 6 mm in size. Latex fractions registered significantly higher growth inhibition than that of broad spectrum antimicrobial drugs. Present study indicates the potential use of shows that both latex and its components and latex as are valuable source of medicinal products/active principles that can be used for treatment of life threatening infectious diseases. Because of higher inhibitory and cidal potential obtained in latexes than the synthetic drugs these that could lead to become efficient phytomedicines mainly to have and develop as complete drug formulations against to control infectious microbes.
GC-MS Analysis and in Vitro Antimicrobial Susceptibility of Foeniculum vulgare Seed Essential Oil  [PDF]
Ravi Kant Upadhyay
American Journal of Plant Sciences (AJPS) , 2015, DOI: 10.4236/ajps.2015.67110
Abstract: Essential oil from seeds of Foeniculum vulgare was extracted on Clevenger apparatus. Essential oil was analyzed on Gas-Chromatography-Mass spectrometry (GC-MS) from which thirty six components were identified, among which 6 major and 30 minor components having different structural formulae and molecular weight representing total 99.98% of oil. Essential was investigated for its antibacterial and antifungal activity against seven infectious microbial pathogens. Paper disc diffusion and serial micro-dilution assays were performed for the determination of inhibition zone (DIZ) diameters and minimal inhibitory concentration, respectively. The Foeniculum vulgare essential oil showed the Diameter of Inhibition Zone (DIZ) ranging from 19.4 ± 0.07 - 26.4 ± 0.09 mm at a concentration level of 28 μg/disc in all the ten strains tested. The minimum inhibitory concentration (MIC) of essential oil against bacterial and fungal strains was obtained in the range of 7.0 - 56 μg/ml. Antibacterial and antifungal activity of Foeniculum vulgare essential oil is due to the presence of certain secondary plant metabolites such as terpenoids, steroids and flavonoids, esters and acids which are identified in the essential oil. The oil components can be further studied for their biological activity and overcome the problem of drug resistance in microbes.
Does Corruption in a Country Affect the Foreign Direct Investment? A Study of Rising Economic Super Powers China and India  [PDF]
Siva Prasad Ravi
Open Journal of Social Sciences (JSS) , 2015, DOI: 10.4236/jss.2015.37017
Abstract:

Many researchers have studied the effect of corruption on Foreign Direct Investment (FDI) and majority of them have come to the conclusion that higher levels corruption in a country deter FDI. This paper is a case-based comparative study of the effect of corruption on FDI in China and India. Corruption in India has negatively affected FDI, whereas that is not true in China. This study finds that while corruption does affect FDI inflows into a country, the effect also depends on nature of corruption and not only on size of corruption.

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